Former president of the Jawaharlal Nehru University Students' Union (JNUSU) Kanhaiya Kumar and 29 other students of the university have been asked to join the probe into alleged raising of anti-national slogans on the campus in February last year, Delhi Police said.
The notice that is addressed to the JNU vice chancellor contains names of students affiliated to the Left studentgroups which dominate the campus politics.
Some of the students, whose names figure in the notice, including AISA (All India Students' Association) leader Shehla Rashid, and Aprojitha Raja, the daughter of CPI national secretary D Raja, were active in a movement demanding release of the three students who were arrested in the case.
The notice says, "For the purpose of investigation some students are to be interrogated in this case. You are hereby informed through this notice to direct following students of JNU to remain present at Administrative Block of JNU (sic)."
"They have been given time by the Delhi Police Special Cell to be present at the administrative block of JNU from 12 p.m. onwards between April 28 and April 30," a senior police officer said.
"Their statements will be recorded as the Investigating Officer has been directed to start the probe afresh," the officer told IANS, adding that "Legal action will be taken if the students failed to join the probe".
A fresh probe was ordered by the top brass of Delhi Police, which went through the draft charge sheet prepared by the Special Cell.
The Legal Wing, which also got to study the draft, found that more probe was required to prove their offence, the officer said.
"The Investigating Officer has been told to complete the recording of the students' statements within three days," he added.
The police haven't even filed a charge-sheet in the case and are examining witnesses.
There is a likelihood that apart from the three students named in the FIR--former JNU students' union president Kanhaiya Kumar, Umar Khalid and Anirban Bhattacharya-- more people might be named in the charge-sheet, whenever it is filed.
A final report along with the draft charge sheet was submitted to Delhi Police Commissioner Alok Kumar Verma in January. The officers connected with the probe had then said that he would give the go-ahead to file the charge sheet.
"Since it is a case of sedition, prior approval of the Lt. Governor's office is also required," he said.
"The draft report said there is enough evidence to prosecute Umar Khalid and Anirban Bhattacharya for sedition. It identified nine 'outsiders' who raised anti-India slogans," the officer said.
The case was transferred to the Special Cell in March 2016.
The Patiala House Court in August 2016 granted regular bail to JNU Students Union President Kanhaiya Kumar and two others -- Khalid and Anirban -- in the sedition case.
The Delhi High Court in September 2016 extended the interim relief given to Khalid and Anirban, who have also been charged with sedition.
JNUSU condemns notice
The JNU students' union, in a statement, condemned the notice and called it a "criminal agenda" of destroying the university.
"We see this as another attempt to target and threaten students and ultimately to fulfil the government's criminal agenda of destroying a university where the battle of ideas and critical thinking are well-cherished practice," read the statement.
The arrest of Kumar, Khalid and Bhattacharya on charges of sedition for allegedly organising an event against hanging of Afzal Guru had triggered a huge controversy with the opposition political parties slamming the police for "working at the behest of ruling BJP".
The controversial programme organised last year sparked an outrage after allegations surfaced that anti-national slogans were raised in the university.
The arrest of Kumar catapulted him to national fame and resulted in student protests across the country.
After footage of the event was found to be authentic, some students, including two Kashmiri students, were questioned by the Special Cell sleuths last year.